Sediment Control System

ABSTRACT

A sediment control system for a contaminated source, comprising an intake system for reversibly diverting flow from the contaminated source to a pipeline extending from the intake system to a plurality of spaced discharge outlets in a low turbulence zone within a water body to minimize mixing of the contaminated source flow with the water body. The source may be a stream, an industrial discharge, a construction site siltation settlement pond, a community storm drain, or a mine tailings source, The water body may be a lake, an ocean, a settlement pond, or a water reservoir.

FIELD OF THE INVENTION

The present invention relates to water treatment. In particular, theinvention relates to systems for reducing contamination of water bodiesby silt or sediment.

BACKGROUND OF THE INVENTION

Suspended silt or sediment in water bodies can be a significant issuefor fish habitat and human water consumption. Small quantities of siltin streams entering a large water body can result in contamination ofthe entire water source. Large water bodies can be contaminated by smallsources of contaminated silty water. One or a few small streamscontaminated with silt can cause widespread silt issues within a muchlarger water body such as a lake or reservoir.

Silt in water reservoirs can be difficult and expensive to resolve oncethe entire water source has been affected. Even minute levels ofsuspended sediments can be a significant health concern and an expensiveissue to resolve. Water quality issues arc becoming a much more heavilyscrutinized public health issue. Acceptable silt levels in drinkingwater reservoirs are constantly being reduced to avoid any potentialissues.

An easy and inexpensive solution to suspended sediments woulddrastically reduce water treatment costs.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described in further detail in accordancewith the following drawings where;

FIG. 1 depicts a top view of one embodiment of the sediment controlsystem of the invention;

FIG. 2 depicts a side view of the embodiment of FIG. 1;

FIG. 3 depicts another embodiment of the sediment control system of theinvention showing the flow control feature;

FIG. 4 depicts a side view of the embodiment of FIG. 3 showing theconcrete weights which hold the pipe in place near the bottom of thewater body; and

FIG. 5 depicts a cross-sectional view of the pipeline showing flows intothe non-turbulent deep water area of the water body.

It is to be expressly understood that the description and drawings areonly for the purpose of illustration and as an aid to further clarifythe descriptive text of the present invention and are not intended tolimit the parameters and potential applications of the invention.

SUMMARY OF THE INVENTION

There is provided a sediment control system for a silt contaminatedsource, comprising an intake system for reversibly diverting flow fromthe contaminated source to a pipeline structure having proximal anddistal ends, the pipeline extending from the intake system to a lowturbulence zone within a water body; wherein the distal end of thepipeline further comprises a plurality of discharge outlets selectivelyspaced to minimize mixing of the contaminated source flow with the waterbody.

The pipeline structure may include a pipeline submerged along the bottomof a water body, the system further comprising submersion means formaintaining the distal end of the pipeline near the bottom of the waterreservoir. The submersion means may be one or more concrete weightsdistributed along the distal end of the pipeline.

The pipeline structure may include a floating horizontal pipelineportion extending from the edge of the water body to a positionvertically above the low turbulence zone, and a submerged verticalpipeline portion extending from the floating portion to the dischargeoutlets at the bottom of the water body.

The contaminated source may be a stream, an industrial discharge, aconstruction site siltation settlement pond, a community storm drain, ora mine tailings source. The water body may be a lake, an ocean, asettlement pond, or a water reservoir. The intake system may be a dam ora head pond.

The system may include means for replenishing the watercourse, which maybe a water pumping system to move water from the water reservoir to thewatercourse downstream of the intake system.

The intake system further may include a flow control system, a sedimentmonitoring system, a flow directional control valve, and a screen forremoving large granular particles and debris.

The sediment control system may include a fish diversion structure toallow fish to bypass the intake system, an overflow management system,and flushing means for clearing residual sediment from the pipeline.

There is further provided a method of controlling sediment in a waterbody fed by one or more contaminated sources, comprising the steps ofdiverting a portion of the silt-contaminated water of at least one ofthe silt-contaminated streams into an intake system; transferring thesilt-contaminated flow into a pipeline extending from the intake systemto a low turbulence zone within a water body; and discharging thesilt-contaminated flow through a plurality of selectively spaceddischarge openings in the distal end of the pipeline. The method mayinclude the additional steps of monitoring the sediment levels in theone or more contaminated sources; adjusting a directional flow controlvalve to select the portion of the contaminated water to be divertedinto the intake system; and replenishing the contaminated sources withwater piped from the water body.

There is also provided the use of the sediment control system of theinvention for reducing silt contamination in a stream, for safelydischarging contaminated industrial sources, for storm drain discharge,for industrial effluent settlement, and for mine tailings settlement.

DETAILED DESCRIPTION OF THE INVENTION

The invention comprises a sediment control system designed to manage thesuspended sediment problem created in large lakes, reservoirs or otherwater bodies by contaminated sources, such as contaminated streams,entering the water body. Small streams with relatively small volumes ofwater but with significant sediment content can contaminate much largerreservoirs. As well, larger streams can carry sediment and causecontamination. Sediment in reservoirs used for drinking water can be acostly problem to deal with for communities. Even small levels ofsediment can create health hazards. Prior art solutions require costlyfiltration systems to deal with the sediment.

Drinking water contamination is becoming a critical issue in many partsof the world. Industrialization and increasing pollution are continuingto threaten already heavily utilized water sources. Excessivesedimentation further complicates the pollution issues. In many advancedcountries, the sediment issue and resulting water quality concerns areincreasing in priority as the evidence of their impacts increases.Acceptable sediment levels in drinking water reservoirs are continuallybeing lowered. As a result, an inexpensive and effective solution toexcessive sediment is increasingly important. The more effective andinexpensive the solution, the more widely it will be implemented.

Small streams can easily be heavily laden with sediment under certainrunoff conditions. Even small streams can easily contain sufficientsediment to contaminate much larger water bodies such as lakes andreservoirs. Fine silt and clay particles can remain in suspension forvery long periods. Large water bodies are subject to continual wind,current and flow conditions which complicate the settlement of suspendedsediments.

Small or large contaminated streams entering large water bodies cancreate significant sediment issues which are very costly to resolve andcan persist for long periods of time.

The proposed sediment control system involves an intake structure on theproblem stream which directs any contaminated flows into a pipeline. Thepipeline is of sufficient size to carry the normal stream flow. The flowwould be selectively directed into the pipeline when the stream iscontaminated. Otherwise the stream flow would follow the normal route tothe reservoir. The intake structure would contain a sediment monitoringsystem and a directional control valve.

As depicted in the drawings, according to one embodiment, the flow fromthe contaminated source 2 is diverted by an intake 4 into a pipeline 6.The pipeline runs from the intake out into a water body 8 such as a lakeand may secured to the bottom 10 of the water body with concrete weights12. The water at the lake bottom is generally much more static and lessprone to constant circulation and mixing, presenting a low turbulencezone 14 within the water body. In contrast, surface water is subject toconstant movement and mixing. The pipeline has a plurality of dischargeoutlets 16 located close to the distal end 18 of the pipe to distributethe sediment laden water over a given area. The discharge system wouldbe designed to distribute the water over an area while minimizing themixing with the larger reservoir. The contaminated water would remain inthe relatively static bottom layer, the low turbulence zone and wouldsettle out much more quickly. The discharge system preferably would bein the most appropriate location in the reservoir. This would generallybe a large area located at a deeper elevation with minimal current andcirculation.

The proposed sediment control system may work for other types ofcontaminants that could be deposited appropriately in deep lake bottoms.These would include mine tailing treated water or, in some cases, minetailings themselves.

The solution of the present invention is a system in which thecontaminated stream flows may be directed into a pipeline which runs outinto a water body and is weighted to sit on the bottom of the waterbody. The pipe would extend down to the bottom of the lake where thewater is relatively still. The pipe would have openings at the distalends to allow the sediment contaminated water to discharge 21 from thepipe.

The contaminated water would be dispersed over a distance to ensure theflows exiling the pipe were relatively slow moving. This would minimizethe disturbance and mixing of the contaminated water. By minimizingmixing, the risk of affecting the entire water body is reduced.

If a large and deep lake receives small inflows of contaminated water,it would be relatively easy to contain the problem. In other lakes whichare smaller, shallower and subject to larger contaminated flows thedesign of the system would need to be more carefully managed to minimizemixing. Each location would require individual assessment andmanagement.

The depth of the water body and the amount of flow in the lake wouldaffect the water movement at various depths in the lake. The amount ofcontaminated water relative to the total flow would have to beevaluated. Each scenario would be different as would the effectivenessof the proposed solution.

Stream flows would be directed into the pipe only when the water iscontaminated. Normal clean stream flows would be directed down thenormal stream route. A metered monitoring system and directional valve22 would need to be installed to determine and control flow direction.

Fisheries issues would need to be considered. Measures would need to bein place to avoid fish moving down the pipeline. The fish could be finemoving down the pipeline to deep water, or there could be issues. Thefish could also become stranded in the pipeline which could be aconcern. Heavily contaminated streams however would alreadysignificantly damage any fish already in the stream.

The issue of directing flows down a pipeline and potentially sloppingflow in the creek could be a problem as well, especially if fish arepresent. Water from the lake or reservoir may need to be pumped up tothe intake area to compensate for any stream losses. This would dependon the distance of the intake valve from the lake.

An intake system would be required to direct stream flows into thepipeline. A small dam or even a head pond 24 may be required to producesufficient head to move enough water down the pipeline.

The surface water on a reservoir or lake would be circulating and mixingmuch more than water at deeper levels. Contaminated water entering atthe surface will be thoroughly and quickly mixed with the existing lakewater.

Water at greater depths would be relatively static and less subject toconstant circulating and mixing. Any contaminated water that is directeddown to the lower levels of the lake and dispersed carefully shouldremain in a relatively small and restricted area. The slow movement ofthe contaminated water would minimize any mixing with existing water.Contaminated stream flows may be only a very infrequent event and theactual volume may be quite small. Rather than mixing and contaminatingthe entire lake the silty water would remain in a small area in analmost static position. This is the ideal location for the contaminatedwater to be located to allow it to settle quickly with minimal mixing.

High-density polyethylene pipelines are often floated out into waterbodies and sunk to the bottom to be used as effluent disposal systems.Concrete weights are often installed at the ends to ensure the pipelinedocs not move. Openings at the ends are installed to allow the effluentto discharge. Concrete and steel pipelines can also be utilized aseffluent discharge pipes.

Effluent pipelines are generally located to encourage rapid dispersaland dilution of the effluent. The best location is usually in a fairlyrapidly moving water body to ensure mixing and dilution. The effluent isgenerally encouraged to mix and dilute with the surrounding waterbecause this promotes breakdown and environmental treatment of theeffluent.

The intention of the proposed silt system differs from a conventionaleffluent system because the contaminated water is discharged in a mannerwhich minimizes any mixing and movement. The best way to treat thesediment laden discharge is to contain it to a small area and avoidmixing and excessive movement.

Silty water can contain fine suspended particles which settle outslowly, but it can also contain heavier particles which settle quickly.Potential silting and clogging of the discharge pipeline would have tobe considered. A flushing process may need to be included in the designto overcome such silting and clogging.

Environmental issues tend to be reduced in deep water locations. Fishand vegetation is a less significant factor in deeper water. Often thereis very little vegetation or fish. Discharge of contaminated silty wateris ideally located in deep static locations.

Any debris located on the bottom of water bodies would need to beconsidered when placing a pipeline on the bottom.

The actual source of suspended particles can be located a distance fromthe actual main water body. A relatively small source can contaminate alarger stream well before it enters the lake or reservoir. In somesituations, it may be easier to locate the actual source of the maincontamination and potentially pipe that water to the lake even if it isa considerable distance. This much smaller flow from the contaminationsource can be piped down to the lake bottom, rather than piping the muchlarger stream. Each situation would be different and would needindividual assessment.

Water temperature concerns may be a factor in some situations. Streamflows may be warmer or colder than the water located at the lake bottom.There may be fisheries concerns with moving surface water to the bottom.In addition, there may be other environmental factors to consider whenmoving surface flows to deep water locations. In some cases, it may beimportant to minimize flows to the lake bottom to reduce any of theseimpacts.

There are other situations where this system may be helpful, including,among others, mine tailing flows. Mine tailing flows are often treatedand then transitioned through various settlement ponds before beingdischarged to water bodies. While these flows are not released untilthey reach acceptable levels they can still impact water bodies overtime. If these flows can inexpensively be piped down to deep waterlocations and settle out over time this could greatly reduce the impactsfor minimal cost.

For a mine tailings application, the contaminated water would need to bedischarged over a distance to minimize movement and mixing. The designwould need to consider the most effective method of containing the waterwhile minimizing movement and mixing. It would have to be dischargedover a large enough area to allow for years of operation. Buildup ofsediment in the pipeline would need to be considered.

Mine tailings sediment is generally controlled with settlement ponds ofvarious sizes. The sediment size determines how long it takes formaterial to settle out. Fine suspended sediments can take long periodsof time to settle out. Larger sediments settle out quicker.

The proposed system essentially utilizes large parts of lakes orreservoirs as settlement ponds or areas. Deep locations in thereservoirs are often essentially static. The water does not circulate ormix with surrounding areas.

Creeks and streams generally carry both large and small sediments aspart of their normal function. Boulders, rock, gravel and fine sedimentsare all carried by streams.

Larger particles generally settle out quickly. It is the fine suspendedparticles which create the longer term problems. There is no benefit tothe larger particles entering the proposed pipeline system running tothe lake bottom. The coarser heavier particles should be removed beforeentering the pipeline. The intake system would need to allow for this.

A conventional hydro penstock system generally considers sediments inthe design. Coarse sediments and debris is screened or settled outbefore entering a penstock. A hydro system can handle some sedimentbecause the high water flow will move out any debris and sediment.

In the proposed system, the water flow at dispersal would by design bemuch slower. The potential for sediment build up is greater and wouldneed to be considered.

The intention of the pipeline outfall system is to dispense the sedimentladen water over a given area determined by the design.

Various factors will determine how the outfall system should bedesigned.

Ideally the sediment should be spread out and not concentrated in asmall area. However, the sediment should still be contained in an areaof static water. It should not be allowed to circulate into the greaterwater body and risk contamination of larger areas.

The character of the water body and how the water circulates would needto be evaluated to determine the design of the system. Reservoirs andlakes vary considerably in their size, shape and water flowscirculation. The character of the static or slow moving areas would alsoneed to be evaluated.

The system should also move the water with sufficient volume toconstantly flush the sediment from the pipes. It should flush the pipeswithout creating too much velocity and thereby too much mixing with thesurrounding water.

The design of the pipeline would be a factor in how the water isdispensed. The pipe size and slope would impact the flowcharacteristics. The pipeline may need to consist of various sizes tomodify the flow rates as the water is dispensed at various locations.

The dispersal pipe openings would likely vary in size and location onthe pipeline to optimize the distribution of the water.

The purpose of the intake system is to direct the creek flows into thepipeline only when the water contains excessive sediment. The intakemust be structured such that the water is forced down the pipelinerather than overflowing around the pipe. An overflow system wouldhowever always be required in the case when the creek flows exceednormal high flow levels. This would be designed to happen only every fewyears.

A sediment meter and directional valve would be required to direct thecreek flows into the pipeline only when the sediment levels reach acertain level. If the sediment levels are below an acceptable level thewater would flow down the normal creek route to the lake or reservoir.

The directional valve would be constructed such that the creek wouldfunction normally when flows are clean. There would be minimal impactsto habit and water quality.

The intake would be designed to screen out larger granular sediments anddebris.

The intake system may need to allow for fish controls as well.Conventional hydro intake structures must account for any fish impacts.

When creek flows are redirected into the pipeline the creek flow belowthe intake will be disrupted. This is similar to some hydro projects andstrict guidelines are required to manage this. A hydro project isrequired to maintain a minimum flow in a creek at all times. Thisdepends on the existence of any fish.

Water from the reservoir or lake may need to be pumped up to the intaketo account for the lost creek flows. Other solutions are also possible.

Alternatively, some sediment laden water could be allowed to remain inthe creek to support any fish. This would contaminate the lake with somesediment but at a much lower level.

The location of the intake must also be considered. Ideally it should berelatively close to the lake to reduce the pipeline length. It alsoneeds to function effectively. Moving the intake upstream may allow itto be less expensive or operate more effectively.

There is also the possibility that a smaller minor stream is the maincontributor of sediment. This stream may be much farther upstream whereit enters the main stream. It may be cost effective to construct a muchsmaller intake on this minor stream and install o longer but smallerpipeline down to the lake.

Each location would have different characteristics and requirealternative designs and solutions.

Modem hydro intake systems are generally automated, especially when theintakes are in isolated locations. The proposed system could also beautomated to function remotely. The system could be monitored andoperated remotely to handle the current and expected stream andreservoir conditions.

As the system operated and monitoring continued the actual function ofthe system could be refined to improve efficiency. The reservoir waterconditions could be monitored under various system scenarios to furtherrefine efficiency.

The present invention offers a very effective and low cost way to dealwith sediment in lakes and reservoirs. It may also prove to be usefulfor the treatment of other water contamination concerns.

Each part of the system could be refined to operate more effectively.The character of the sediment and how it is handled could be refined.

The present invention may be used for industrial discharge solutions.Many locations in the world discharge contaminants into water bodieswith little regard for how it disseminates. If an inexpensive system todischarge it to deep water locations is available, it would be animprovement. Even advanced countries only treat industrial output waterto a certain level, then discharge it. That treated discharge would bebetter to be discharged to deep water locations to continue tobiodegrade.

The present invention may be used for storm water dispersal. Even highlyadvanced cities around the world often discharge storm water runoffdirectly into water ways. It is deemed as a low risk and is most easilyand cost effectively dealt with by direct dumping into water bodies.Storm water, while deemed a low risk, still contains significantcontaminants. Dumping it into the main water body will lead to mixingand widespread contamination. Discharging it to deep locations willreduce impacts to the main water bodies. Contaminants in large waterbodies will eventually settle to the bottom, but it will take longperiods because oceans are in constant circulation and mixing whichslows down the settlement process. Contaminants discharged to deeplocations will settle out much more quickly.

The present invention may also be used for mine tailings discharge. Minedischarge water is generally treated and then directed through varioussettlement ponds before being returned to the normal stream or riversystem. The water is treated and/or settles out until it reachesacceptable levels. Over time however the discharge still can haveimpacts on large water bodies. If the discharge however was directed tothe lake bottom to settle further over time, it would impact the lakemuch less.

In prior art approaches, mine tailings in some cases were dischargeddirectly to water bodies with minimal treatment, depending on the typeof mine. Some mines in Canada sent tailings discharge into lakes asrecently as the last 20 years. Mine tailings are generally contained intailings ponds for eternity in some eases. However, these ponds can bevery unstable, especially in earthquake conditions.

There are numerous places around the world where mine tailings continueto be discharged directly into water bodies. Under normal conditionsthese tailings would contaminate the entire water body until theysettled out. If tailings were continually discharged the lakes wouldnever recover.

If tailings were deposited to lake bottoms directly and allowed tosettle relatively quickly in undisturbed environments, contamination ofthe lakes would be dramatically reduced. If it could be accomplishedinexpensively the chances of its implementation would be increased.Deposition and settlement of tailings in deep lakes would be performedsimilarly to the proposed system of dealing with sediment laden water.

High quality water can be highly beneficial as drinking water. However,it can be valuable for industry as well. Water sources which haveminimal sediment content are prized for various industrial processes.Link Lake in Ocean Falls was one of the main reasons the Ocean FallsPulp and Paper Business was located there for many years. Ocean Fallswas one of the top producing mills in BC for many years. The quality ofthe water in Link Lake is still well known to industry as a high-qualitywater source, hence the reason for locating an on-land fish rearingfacility in that location. Various other businesses have consideredlocating to Ocean Falls to take advantage of the water source. Link Lakeis so valuable because the lake is very long which allows abundant timefor the sediment to settle out.

The proposed system includes a stream intake structure which isconnected to a pipeline which runs out into the lake and is situated onthe lake bottom. Dispersal openings at the end of the pipelinedistribute the contaminated water to the static bottom layer of water.The contaminated water remains in the static bottom layer of lake waterand settles out rather than mixing with the main reservoir water.

The intake structure is located on the contaminated stream relativelyclose to the lake. The intake directs the stream flow into the pipeline.The water is directed into the pipeline only when it is contaminated.Clean stream flows are allowed to follow the normal stream route.

The intake structure includes a sediment meter and directional valve.The flow is directed into the pipeline only when contaminated above acertain level as determined by the sediment meter. Otherwise the flowfollows the normal stream route to the lake.

The intake structure includes fish and debris control devices whichminimize any fish or large debris particles from entering the pipeline.The intake system which may include a head pond, limits the amount oflarger size heavy granular rocks from entering the pipeline.

The pipeline is sized to handle the normal stream flows. An overflowsystem would be included to handle the eventuality of an excessivestream flow which exceeds the pipeline capacity.

The pipeline carries the contaminated water down to the bottom of thelake or reservoir where water is generally static or very slow moving.

The pipeline has distribution openings close to the end. The openingsdistribute the silty water over a given design discharge area. The size,spacing and orientation of the openings will vary with the designcriteria. The intention is to disperse the silty water over an areawhile ensuring the material remains within the area of relatively staticwater. The sediment laden water once distributed should remainrelatively static and should settle out quickly.

The pipeline may be subject to some buildup of silt over time. Thevelocity of the water in the system should be designed to distribute thewater while minimizing the silt buildup within the pipeline.Alternatively, a flushing system may need to be incorporated to ensuresediment buildup can be removed on a regular basis.

The pipeline distribution system should be located as much as possiblein an area of static or slow moving water. This will facilitate morerapid settlement of the sediment. It will also minimize any circulationand mixing with the surrounding water. A conventional effluent dischargesystem encourages pipeline discharges in areas of rapidly moving waterto encourage rapid mixing and dilution of the effluent. This facilitatesdissemination over a larger area and increased environmentalbiodegradation. This is directly opposite of the intention of thesediment distribution system.

A conventional effluence discharge system would want to disperse theeffluent rapidly to discourage any blockages or backups in the system.The velocity of the discharge would be designed to disperse and mix withthe surrounding water as much as possible. The sediment control proposedsystem would be designed to discharge the silty water only enough todistribute it over a limited area. The velocity would be kept as slow aspossible to minimize dissemination and mixing with surrounding water.The velocity would be just sufficient to disseminate the material and tominimize settlement of the sediment.

The intake system would include an automated sediment meter to monitorand control the direction of the stream flow. When the sediment reacheda certain level, the meter would initiate the directional valve. Thevalve would redirect the stream flow into the pipeline. Conventionaleffluent systems do not have this type of directional control system.

The discharge system would be located as much as possible in an areawhere the water is static or slow moving. The most efficient way totreat sediment laden water is to maintain it in a static or very slowmoving location for as long as possible. This is the best way to promotesediment settlement. Alternatively, the best way to promote treatment ofconventional effluent is to encourage wide distribution and continualmixing.

Sediment laden water should be directed as deep in a reservoir or lakeas possible. Sediment in any conventional large water body willgenerally settle to the bottom over time. By dispensing the sedimentwater directly to the bottom or close to the bottom will just facilitatethe normal process that occurs in all water bodies. It will also avoidwide spread contamination of the entire water body and the longer termsettlement process which occurs as a result. Water at the bottom of areservoir is generally more static or slow moving which furtherencourages settlement. Alternatively, a conventional effluent pipelinedischarges into water which is rapidly moving but not necessarily deep.The effluent because of its nature is discharged at a minimal depth, butjust to avoid any surface impacts. The intention is to place thematerial at a minimal depth within rapidly moving water to ensure rapidmixing, and dissemination over a large area. Placing the effluent toodeeply will likely mean it is in slower moving water with less chance ofmixing and dissemination.

Sediment laden water placed at lake bottoms will have lowerenvironmental impacts. At deeper elevations the habitat and wildlifewill be much less, and the sediment will have much less impact.Conventional effluent treatment is best if it is located anddisseminated in an area of high habitat and wildlife. This willencourage the more rapid treatment and biological breakdown of theeffluent.

Sediment laden water is managed most effectively by being contained in alimited area and allowed to settle with as little disturbance aspossible. Conventional effluent is treated more effectively by mixing,dilution and dissemination as much as possible. The more widely it isdisseminated the more it will be exposed to biological breakdownmechanisms. The placement and dispersal systems have radically differentapproaches and intentions when placing sediment laden water versuseffluent.

Conventional methods to control sediment laden water is to avoid anycontact with larger water bodies. The preferred approach is to isolatethe water in settlement ponds or process it through sediment removalsystems. Generally, once the contaminated water is in contact with alarge water body, mixing and dispersal is inevitable and removal of thesediment becomes significantly more complicated. Dispensing the sedimentladen water into a large water body at depth in static locations is adrastically different approach than conventional systems. The criticalpart of the approach is to ensure the water is dispensed in a deep waterlocation which is static and to minimize mixing with surrounding water.This essentially places the material into a confined settlement areawithin the larger water body.

The effectiveness of the system depends on how easily the contaminatedstreams can be isolated from the majority of flow into a water body. Ifa few small streams arc involved and easily be contained the systemcould be very effective. If the contaminated streams are a large portionof the lake inflow, then the treatment system may be less effective.

The size of the water body relative to the info volumes is also animportant factor. The larger the volume of static and deep water thereis relative to the contaminated inflow volume will determine theeffectiveness of the system. The system will vary in effectiveness witheach reservoir scenario.

According to an alternate embodiment of the present invention, theintake system and pipeline structure may be a temporary structure tohandle temporary contaminated water situations.

According to another embodiment, the discharge pipe may float out on thetop of a reservoir to a selected location and extend vertically downwardto the bottom of the water body with a dispersal pipe located on thebottom. This embodiment may be moved to discharge in various locations.

As has been indicated, there are numerous potential applications for thepresent invention where contaminated water is best placed at lowerlevels of the water body in static locations where it will not mix withthe main water body.

For example, the system of the present invention may be used forimproved mine tailing or industrial settlement pond operation. Prior artsettlement ponds operate by adding new contaminated flows directly intothe main water body, resulting in constant recirculation and mixing ofthe entire water body, thereby drastically reducing the efficiency ofthe settlement process. According to the method of the presentinvention, new contaminated flows may be placed slowly to the bottom ofthe settlement pond without disrupting and mixing with the mainwaterbody, resulting in much quicker settlement. The capacity of miningsettlement ponds can limit the productivity of a mining operation.Settlement ponds and disposing of the runoff water can be an enormouscost and limiting factor to productivity and profitability. Improvingsettlement pond efficiency can improve the operation. Disposing of someof the run-off water earlier by deep static discharge can also improvesettlement pond efficiency. Silt settlement pond management would alsobe improved in the same maimer as industrial ponds. If silt laden wateris slowly distributed to the bottom of settlement ponds without mixingwith the main water body, then settlement will result much quicker.

According to one embodiment, mine tailings may be placed into a lake orocean deep static zone, rather than into a settlement pond if thetailings may be safely placed in such location. In some cases, deepstatic zone discharge of tailings will be safer that in a settlementpond which may be subject to earthquake failure.

Another application may be water which has become contaminated or siltyfrom construction operations and which is to be discharged from a worksite to a water body. For some industrial discharges such as heatedwater or some chemical or radioactive contaminants, the discharge may bebest handled by deep static discharge into a water body according to themethod of the present invention. Similarly, agricultural discharges suchas water bearing high levels of fertilizer or organic contaminants maybe appropriate for deep static discharge into water bodies.

It would be advantageous to direct community storm drains using thesystem of the present invention to deep, static locations within waterbodies.

In an industrial context, as well as providing a solution forcontaminated discharge, the present invention can improve the quality ofsource water for industry by reducing the silt contamination of waterbodies used as industrial water sources. With respect to fisheries, fishhabitat would be improved through a decrease in siltation andcontamination.

It is to be understood that any low turbulence zone within a water bodymay be appropriate for settlement according to the present invention,including oceans.

It will be appreciated by those skilled in the art that other variationsof the preferred embodiment may also be practiced without departing fromthe scope of the invention.

1. A sediment control system for a silt contaminated source, comprising:a. an intake system for reversibly diverting flow from the contaminatedsource to a pipeline structure having proximal and distal ends, thepipeline extending from the intake system to a low turbulence zonewithin a water body; wherein the distal end of the pipeline furthercomprises a plurality of discharge outlets selectively spaced tominimize mixing of the contaminated source flow with the water body. 2.The sediment control system of claim 1, wherein the pipeline structurecomprises a pipeline submerged along the bottom of a water body, thesystem further comprising submersion means for maintaining the distalend of the pipeline near the bottom of the water reservoir.
 3. Thesediment control system of claim 2 wherein the submersion meanscomprises one or more concrete weights distributed along the distal endof the pipeline.
 4. The sediment control system of claim 1, wherein thepipeline structure includes a floating horizontal pipeline portionextending from the edge of the water body to a position vertically abovethe low turbulence zone, and a submerged vertical pipeline portionextending from the floating portion to the discharge outlets at thebottom of the water body.
 5. The sediment control system of claim 1,wherein the contaminated source is selected from the group ofcontaminated sources comprising a stream, an industrial discharge, aconstruction site siltation settlement pond, a community storm drain,and a mine tailings source.
 6. The sediment control system of claim 1,wherein the water body is selected from the group of water bodiescomprising a lake, an ocean, a settlement pond, and a water reservoir.7. The sediment control system of claim 1, further comprising means forreplenishing the watercourse.
 8. The sediment control system of claim 7,wherein the means for replenishing the watercourse comprise a waterpumping system to move water from the water reservoir to the watercoursedownstream of the intake system.
 9. The sediment control system of claim1, wherein the intake system is selected from the group of intakesystems comprising a dam and a head pond.
 10. The sediment controlsystem of claim 1, wherein the intake system further comprises a flowcontrol system.
 11. The sediment control system of claim 1, wherein theintake system further comprises a sediment monitoring system.
 12. Thesediment control system of claim 1, wherein the intake system furthercomprises a flow directional control valve.
 13. The sediment controlsystem of claim 1, wherein the intake system further comprises a screenfor removing large granular particles and debris.
 14. The sedimentcontrol system of claim 1, further comprising a fish diversion structureto allow fish to bypass the intake system.
 15. The sediment controlsystem of claim 1, further comprising an overflow management system. 16.The sediment control means of claim 1, further comprising flushing meansfor clearing residual sediment from the pipeline.
 17. A method ofcontrolling sediment in a water body fed by one or more contaminatedsources, comprising the following steps: a. diverting a portion of thesilt-contaminated water of at least one of the silt-contaminated streamsinto an intake system: b. transferring the silt-contaminated flow into apipeline extending from the intake system to a low turbulence zonewithin a water body; and c. discharging the silt-contaminated flowthrough a plurality of selectively spaced discharge openings in thedistal end of the pipeline.
 18. The method of claim 17, wherein thecontaminated source is selected from the group of contaminated sourcescomprising a stream, an industrial discharge, a construction sitesiltation settlement pond, a community storm drain, and a mine tailingssource.
 19. The method of claim 17, wherein the water body is selectedfrom the group of water bodies comprising a lake, an ocean, a settlementpond, and a water reservoir.
 20. The method of claim 17, furthercomprising the additional initial steps of: a. monitoring the sedimentlevels in the one or more contaminated sources; and b. adjusting adirectional flow control valve to select the portion of the contaminatedwater to be diverted into the intake system.
 21. The method of claim 17,further comprising the additional step of replenishing the contaminatedsources with water piped from the water body.
 22. Use of the sedimentcontrol system of claim 1 for reducing silt contamination in a stream.23. Use of the sediment control system of claim 1 for safely dischargingcontaminated industrial sources.
 24. Use of the sediment control systemof claim 1 for storm drain discharge.
 25. Use of the sediment controlsystem of claim 1 for industrial effluent settlement.
 26. Use of thesediment control system of claim 1 for mine tailings settlement.